1. Field of the Invention
This invention generally relates to an information recording apparatus, an information reproducing apparatus, an information recording method, an information reproducing method, and computer programs related thereto. This invention particularly relates to a method and an apparatus for recording information representative of moving pictures and at least one still picture on a recording medium in such a manner as to allow a search for a desired scene in a moving-picture stream to be conducted during playback, a method and an apparatus for reproducing information representative of moving pictures and at least one still picture from a recording medium and searching a moving-picture stream for a desired scene, and computer programs related thereto.
2. Description of the Related Art
Japanese patent application publication number 2004-72148 discloses an audio-visual data recording apparatus including a prism, a first CCD device for capturing low-resolution moving pictures, and a second CCD device for capturing high-resolution still pictures. The prism splits an incoming light beam into two beams applied to the first and second CCD devices respectively. The first CCD device generates a video signal representing a stream of moving pictures. The second CCD device generates a video signal representing an updatable still picture. The moving-picture signal is compressed according to the MPEG standards. The still-picture signal is compressed according to the JPEG standards. The compressed moving-picture signal and the compressed still-picture signal are simultaneously recorded on a common memory card.
Japanese patent application publication number 2000-23094 discloses an information recording apparatus designed to record data representative of a stream of moving pictures and data representative of a still picture or pictures on a magneto-optical disc. In the apparatus of Japanese application 2000-23094, input data representing a stream of moving pictures is compressed on an MPEG basis to generate compressed moving-picture data. When an operation button issues a still-picture capturing signal, a corresponding time segment of the input data which represents one picture in the moving-picture stream is sampled and is then compressed on a JPEG basis to generate compressed still-picture data. Thus, the picture represented by the sampled time segment of the input data is used as a still picture represented by the compressed still-picture data. The compressed moving-picture data and the compressed still-picture data are recorded on the magneto-optical disc in synchronism with a sync signal.
In a picture search system applied to the case where data representative of a stream of moving pictures and data representative of still pictures corresponding to selected ones of the moving pictures are recorded on a common recording medium, information representing the time position of each recorded still picture is used as search position information (an entry point) for a picture or a frame in the recoded moving-picture stream. Generally, it is difficult to effectively conduct a search for a desired picture in a recorded moving-picture steam in response to only such search position information.
In the case where a recorded still picture is used as an index picture and a search is conducted while the time position of the index picture (the still picture) is defined as an entry point for a picture in a recorded moving-picture stream, playback is immediately started from the picture corresponding to the entry point. Sometimes, there is the occasion for a user's decision to capture a still picture. In this case, the occasion precedes the moment of the capture of the still picture. In other words, a picture or pictures in a recorded moving-picture stream which shows the occasion precede the moment of the capture of the still picture. As previously mentioned, the moment of the capture of the still picture is defined as an entry point, and a search causes playback to be immediately started from the picture corresponding to the entry point. Therefore, the picture or pictures showing the occasion are not played back during the search. Thus, in this case, it is difficult to meet a user's request to see the picture or pictures showing the occasion. In order to find the picture or pictures showing the occasion, it is necessary for the user to slightly move back the playback start position and then perform the playback after the conduct of the search.